Shotcrete retaining wall against clay

[petrosoft]

I have to design a cave portal in Napa, CA where the soil is potentially plastic clay, CL, with moderate expansiveness. The contractor would like to cut the 8' wall face and then shotcrete without backfilling. That would leave the wall exposed to the clay as backfill. Is that what is commonly done? Is there a better way to use shotcrete and have granualr fill behind the wall?

Thanks---Petro

 

[dirtsqueezer]

I'm not sure you could protect your wall against potential expansiveness. Even if it were backfilled, it would be compacted anyway, leaving no room for expansion. The only thing I see missing from the equation is a drain fabric like Miradrain for your walls. That would relieve pore pressure in case of infiltration.

Interesting, you're not the only one doing a cave portal in this forum.